Use of an α1-Blocker, YM617, in the Treatment of Benign Prostatic Hypertrophy

Abstract

A recently synthesized alpha 1-blocker, (R)(-)-5-[2-[[2-(o-ethoxyphenoxy)ethyl]amino]propyl]-2- methoxybenzenesulfonamide hydrochloride (YM617), was evaluated in 270 patients with benign prostatic hypertrophy in a double-blind study. After 2 weeks on placebo the patients were assigned at random to 4 groups: group P--placebo, group L--0.1 mg., group M--0.2 mg. and group H--0.4 mg. of YM617. Comparing the placebo to the treatment period, subjective symptoms, such as nocturia and urgency, were significantly decreased in group H (p less than 0.01). The sensation of incomplete voiding was significantly improved in groups M and H (p less than 0.01). However, the differences among the groups were statistically insignificant. Residual urine volume was significantly decreased in groups L, M and H after instillation of saline into the bladder (p less than 0.01) but not in group P. The maximum and average flow rates were significantly increased in groups L, M and H (p less than 0.01) but not in group P. Average flow rate showed significant differences between groups M or H versus group P. Neither orthostatic hypotension nor a decrease in blood pressure was noted. Adverse side effects and changes in laboratory data were all slight and disappeared when the second tests were performed. In summary, the irritative and obstructive symptoms caused by benign prostatic hypertrophy were decreased and urodynamic studies were markedly improved by the alpha 1-blocker, YM617. The drug seems to be useful in the treatment of patients with benign prostatic hypertrophy.

A comparative study of terazosin and tamsulosin for symptomatic benign prostatic hyperplasia in Japanese patients

“…However, a placebo-controlled double-blind study in Japan showed that a 4-week treatment with terazosin 2 mg daily improved subjective symptoms [23]. Although tamsulosin at 0.2 mg daily failed to improve irritative symptoms in the initial study by Kawabe et al [12], two of three irritative symptoms were improved in the present trial. These differences may be attributable to variation in the questionnaires used in the two studies for evaluating the severity of symptoms.…”

“…Subsequently, terazosin has been widely used in Japan at doses of 1± 2 mg daily (the recommended dose established for BPH). Tamsulosin is also used in high doses in Western countries (as high as 0.4 mg daily), but a dose of 0.2 mg daily is recommended in Oriental countries [12,14].…”

Clinical comparison of selective and non‐selective &agr;1A‐adrenoreceptor antagonists in benign prostatic hyperplasia: studies on tamsulosin in a fixed dose and terazosin in increasing doses

“…The mean (sd) Q max measured before treatment was Six patients had abnormal laboratory test values but these changes were not considered to be related to the similar in both groups ( improved the subjective and objective symptoms of Table 4 The incidence of adverse reactions related to study whereas 18 patients in the terazosin group experienced medication a total of 27 adverse reactions considered to be possibly or probably related to study medication and generally that reported by others [21][22][23][24][25][26]. The safety profile as adverse reactions determined from the incidence of adverse reactions and eÂect on blood pressure and pulse rate was similar to …”

“…In studies subjective symptoms as assessed from the IPSS, and objective examinations (e.g. urinary flow rate, PVR, in Japan [21,22], Europe [23][24][25] and the USA [26], tamsulosin, at a dose of 0.2-0.4 mg once daily, produced blood pressure and pulse rate in the supine and standing positions, complete blood cell count, serum biochemistry symptomatic improvement without aÂecting blood pressure and pulse rate in patients with BPH. Further, patients and routine urine analysis) were performed according to the schedule in Table 1.…”

Medical therapy for benign prostatic hyperplasia: sexual dysfunction and impact on quality of life

“…45 In contrast to these agents is tamsulosin, which is highly selective for the a 1A -adrenoreceptor subtype 4,46 and thus has been reported to produce symptomatic improvement of BPH without affecting blood pressure or heart rate and without requiring dose titration (although approximately 20% of patients do require the 0.8-mg dose). 47 Perhaps because of its higher pharmacological selectivity for a 1A -receptors in the bladder neck, seminal vesicles, and vas deferens however, tamsulosin is associated with a significant incidence of ejaculatory dysfunction. It is impossible to know actually if it is abejaculation or retrograde ejaculation.…”